Though bloat is a common problem in dogs, very few people have heard of it or would recognize potential symptoms.
Bloat occurs with no warning in active health dogs.
Bloat is a medical emergency. If you think your dog might have bloat, get veterinary help immediately. Time is really important.
- What is bloat?
- What are the symptoms of bloat?
- What happens as bloat develops?
- Causes of bloat
- What increases the risk of bloat?
- Treatment of bloat
Bloat is also known as Gastric Dilatation-Volvulus or GDV.
Bloat occurs when the stomach becomes overly full with gas. This is dilatation. It can occur with or without volvulus (also called torsion), which is the stomach rotating. Frequently, once the stomach has filled with air, it will rotate.
The common symptoms of bloat are listed below. The first two symptoms are usually present. Not all dogs will have all symptoms.
- Swollen belly
- Retching or trying to vomit
- Shallow breathing or panting
- Abdominal pain (often dog hunches up)
- Pressing on abdomen may make dog react in some way, such as whining
- Tapping the abdomen may produce a hollow sound
- Walking a stiff legged manner
- Restlessness and pacing
If untreated, particularly if there is volvulus, bloat can rapidly progress. Later symptoms include;
- Pale gums and tongue
- Rapid difficult breathing
- Rapid heartbeat
The belly swells due to the trapped gas. Often the stomach will then twist (volvulus). The spleen is attached to the stomach and so rotates with it.
The twisting isolates the stomach since the digestive tract is twisted both above and below the stomach.
Dogs will often retch or try to vomit to try to empty the stomach. Usually nothing will come up, occasionally there will be a little foam and mucous. Many dogs will produce a lot of saliva when they are in pain.
The pressing of the expanded stomach on the diaphragm makes it difficult for the dog to breathe. Pressure on large veins in the abdomen makes it difficult for blood to return to the heart. The reduced flow of blood returning to the heart reduces the oxygen in the blood. This increases the need to breathe, and causes panting.
The twisting of the stomach interferes with the blood supply to the stomach and consequently the cells of the stomach start to die. The trapped contents of the stomach start to ferment resulting in more gas, making the stomach even more distended.
The dog will become dehydrated. The stomach may perforate (puncture). Heart arrhythmias will often start. Small blood clots may start to form.
The dog will go into shock. Collapse and death will follow.
Often the cause of bloat is unknown. Why there is a buildup of gas (and sometimes fluid) and why it is not released is frequently unclear.
Most cases of bloat are thought to be due to swallowed air. Dogs like humans will swallow air, particularly when they drink. The air is usually released by burping. Studies are underway to see why air is not released in bloat.
Once a dog has had bloat, they have a high risk of getting bloat again, particularly if they have not had surgery to reposition the stomach and fix it in place.
The following have been associated with increased risk of bloat.
- Drinking a lot water very quickly (so taking in a lot of air)
- Drinking one hour before or after eating
- Feeding only once a day (large dogs)
- Eating very rapidly
- Elevated feeding bowl (used to think elevation helped)
- Vigorous exercise within 2 hours of eating
- Large dogs particularly those with large narrow chests
- Genetics – if parent has had bloat (may be inherited chest shape and size)
- Older dogs
- Major stress
- Nervous temperament
- Male dogs twice as likely as female to get bloat
Breeds that have been found to have a higher risk of bloating include Great Dane, Saint Bernard, Setters, Weimaraner, Standard Poodle, Bassett Hound and Doberman Pinscher.
If you suspect that your dog has bloat get veterinary help immediately.
Death from bloat can occur quite quickly. Plus the faster the treatment, the less the damage and the increased chance that the dog will not die. Even with treatment more than 25% of dogs die. Some estimates put the death rate at close to 50%.
Usually the first thing the vet will do is to release the air from the stomach. This is done by inserting a tube into the stomach or if this is ineffective by inserting a large needle directly into the stomach.
The dog, usually in shock, will be given IV fluids, pain medication and often antibiotics, and monitored for heart arrhythmias. Often heparin (prevents blood clotting) will be given, since some dogs will be starting to develop small blood clots.
The abdomen will be x-rayed to determine whether volvulus has occurred.
Surgery will allow the stomach and spleen to be evaluated for damage. If there is significant damage it is unlikely that the dog will survive for any period of time. The vet may advise euthanasia.
If the damage is not considered severe, the stomach will be repositioned. Usually the stomach is sutured (stitched) to the abdominal wall to stop the stomach moving again and twisting, this is called gastroplexy. Once there has been an episode of bloat with volvulus the chance of reoccurrence again is very high without gastroplexy.
Bloat is an emergency and can rapidly lead to death. If bloat is suspected get veterinary attention immediately. Better safe than sorry.